JP4659999B2 - Manufacturing method of microwave oven paper cup - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a paper cup for use in a microwave oven.
[0002]
[Prior art]
Conventionally, paper cups have been widely used for hot beverages and instant foods in vending machines. Moreover, although it is not common, the paper cup containing a drink, a side dish, etc. is also cooked directly using a microwave oven. As shown in FIG. 9, the general paper cup P includes a body member 1 and a bottom member 2, and the body member 1 mainly forms a body portion 11 and curls the upper end outward to form a top curl portion 12. The lower end is folded inward to form a folded portion 13. On the other hand, the bottom member 2 mainly forms a bottom surface portion 21, and an outer peripheral edge portion is bent downward at a substantially right angle to form a joint portion 22. The body member 1 and the bottom member 2 are joined by thermocompression bonding with the joint portion 22 of the bottom member 2 sandwiched between the folded portion 13 of the body member 1 and the lower end portion of the body portion 11. A portion where the joining portion 22 of the bottom member 2 is sandwiched and joined is referred to as a yarn twisting portion Z, and the bottom surface portion 21 is raised.
[0003]
[Problems to be solved by the invention]
However, when the contents are put into a general-shaped paper cup P and cooked with a microwave oven, there is a problem that the yarn twisting portion Z at the bottom of the paper cup may be burnt. The cause is considered as follows. The cellulose in the paper material pulp basically absorbs microwave microwaves. Therefore, in the yarn twisting portion Z where the paper overlaps, the paper thickness increases and the heat generation amount increases. On the other hand, since the surface area does not change, the amount of heat released is the same, and the generated heat is accumulated, causing the temperature to rise and causing scorching. However, if the contents are present, it is difficult for the burn to occur. This is probably because the heat generated and accumulated in the paper is taken away by the contents. That is, in the normal paper cup P, as shown in FIG. 9, since it has a structure that has a threaded portion Z as a joining portion of the body member 1 and the bottom member 2, the threaded portion Z is formed on the front side and the back side. Microwave irradiation from both sides, no contact with the contents, and heat is easily generated, which is likely to cause burns.
[0004]
The present invention provides a method for manufacturing a microwave oven paper cup that does not cause scorching in the thread-string portion when contents such as beverages and instant foods are put in a paper cup and cooked in a microwave oven. It is for the purpose.
[0005]
[Means for Solving the Problems]
As a result of studying to solve the above-mentioned problems, the present invention presses the blank of the bottom member in a process of manufacturing a paper cup using paper as a main strength material and using a body member and a bottom member each consisting of a blank. Then, the bottom member forming step before reversing forms a bottom surface before reversing that protrudes upward from the inner surface side of the outer peripheral edge of the bottom member, and a joining portion in which the outer peripheral edge of the bottom member is substantially vertical downward. When, to form a body portion blank is wound into a cylindrical shape of the body member, in the step of forming the top curl curled the upper end of the body portion on the outside, the said pre-inversion bottom member the tip of the joint portion is disposed such that the lower end of the body portion, the joint portion with scissors write Muitojiri portion in the body portion and the folded portion of the lower end folded back on the inside of the barrel , And joining the body member and the inversion bottom member together to form a paper cup A paper cup forming process to form a bottom member forming step of forming a bottom portion of the U-shaped from the inner surface side deformed into a concave shape to below the outer peripheral edge of said bottom member by inverting the inverted front bottom portion downward It is the manufacturing method of the microwave oven paper cup characterized by having provided.
[0006]
According to the method of manufacturing a microwave oven paper cup of the present invention, the shape of the bottom portion of the paper cup can be easily deformed into a concave shape, and contents such as beverages and instant food are put in the paper cup. When cooked, it is possible to obtain a microwave oven paper cup that does not cause scorching in the yarn thread portion.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a partial cross-sectional view of an embodiment of a microwave oven paper cup manufactured by the microwave oven paper cup manufacturing method of the present invention. The microwave oven paper cup A is comprised from the trunk | drum member 1 and the bottom member 2, as shown to FIG. The body member 1 includes a body part 11, a top curl part 12 whose upper end is curled outward, and a folded part 13 whose lower end is folded inward. On the other hand, the bottom member 2 includes a bottom surface portion 21U deformed in a concave shape downward from the inner surface side, and a joint portion 22 whose outer peripheral edge portion is bent downward at a substantially right angle. The body member 1 and the bottom member 2 are joined by thermocompression bonding with the joint portion 22 of the bottom member 2 sandwiched between the folded portion 13 of the body member 1 and the lower end portion of the body portion 11.
[0008]
As shown in FIG. 1B, the bottom surface portion 21U has a U shape that is deformed in a concave shape downward from the inner surface side. Further, as shown in FIG. 1C, the bottom surface portion 21U includes a lower surface portion 21Ua and a wall surface portion 21Ub, and a curved surface portion R is formed between the lower surface portion 21Ua and the wall surface portion 21Ub, and the lower surface portion 21Ua. Is preferably flat, and the wall surface portion 21Ub is preferably close to the folded portion 13 of the body member 1.
[0009]
Further, the curved surface portion R preferably has a curvature radius of 3 to 10 mm, and more preferably 5 to 8 mm. When the curvature radius of the curved surface portion R is less than 3 mm, a pinhole is generated, which causes leakage. On the other hand, when the curvature radius of the curved surface portion R exceeds 10 mm, the yarn twist portion Z is likely to be burnt.
[0010]
In addition, the maximum depth d of the bottom surface portion 21U is desirably 70% or more of the width of the folded portion 13 from the upper end of the folded portion 13 of the body member 1. By setting it to 70% or more, it is possible to block microwave irradiation from the back side of the yarn twisting portion Z in the microwave oven, and to prevent the yarn twisting portion Z from being burnt. If it is less than 70%, there is a risk that the yarn twisting portion Z will burn.
[0011]
Further, the distance x between the lower surface portion 21Ua and the lower end surface X formed by the lower end of the body portion 11 is preferably in the range of less than 8 mm upward and less than 2 mm downward, more preferably in the range of 0 to 3 mm upward. is there. When the distance x is 8 mm or more upward as shown in FIG. 2A, the effect of shielding the microwave from the back side of the yarn twisting portion Z is lost. Further, as shown in FIG. 2B, when the distance x is 2 mm or more downward, the microwave oven paper cup A has a risk of losing stability.
[0012]
Next, although the manufacturing method of the microwave oven paper cup of this invention is demonstrated, first, the paper cup shaping | molding process which produces the conventional paper cup using the trunk | drum member blank 31 and the bottom member blank 32 as shown in FIG. Briefly described. FIG. 4 is a diagram showing an example of a paper cup molding machine that forms a general paper cup. The molding machine 100 is the same as a molding machine for molding a general paper cup, and includes (A) a body winding molding part, (B) a bottom curl part (yarn twist part) molding part, and (C) a top curl molding part. It consists of three parts. The process of this paper cup molding machine will be described in detail. The body blank 31 sent from the feeder is preheated with hot air 101 at the portion to be pasted in a cylindrical shape, and the surface resin is melted (A) It is sent to the molding part. (A) In the body winding forming unit, the body winding paper 102 is wound while being sucked, and heat sealing of the body winding paper is performed. The cylindrical paper heat-sealed in a cylindrical shape is sent to the bottom curl portion (B). (B) At the bottom curl portion, the punched bottom member blank 32 is first sucked and fixed at the position of the mold 110, and then the web is inserted at the position of the mold 111. Next, the portion where the body member 1 and the bottom blank 32 are bonded together is preheated with hot air 101 at the positions of the mold 112, 113, and 114, and the lower end of the body member is folded inward at the position of the mold 115. The body member 1 and the bottom member 2 are integrated by pressure bonding. The cup-shaped product is transferred to (C) the top curl molding unit. (C) In the top curl molding part, the top curl part is fitted into the mold of the mold 120 and applied with lubricant, and the upper end of the body member 1 is curled outward at the positions of the mold 121, the mold 122, and the mold 123, and the top curl part. 12 is formed. Finally, the paper cup is discharged by the mold 124 and manufactured.
[0013]
Next, a method for manufacturing the microwave oven paper cup of the present invention will be described. First, in the method for manufacturing a microwave oven paper cup of the present invention, the inversion bottom member 2 ′ as shown in FIG. This before-reversing bottom member 2 'is composed of a bottom surface portion 21U' before reversing deformed upward and a joint portion 22 whose outer peripheral edge portion is substantially vertical downward, and the shape of the bottom surface portion 21U 'before reversing. Is a semicircular arc shape whose upper side is planar. Further, as shown in FIG. 5B, the maximum height h of the bottom surface portion 21U ′ before inversion is “2 × z + 2>h> 2 × z−8” when the inner width z of the yarn twisting portion Z is set. The value is adapted to the expression "
[0014]
The molding process of the bottom member 2 'before reversal uses a mold 200 comprising an upper mold 201 and a lower mold 202 as shown in FIG. 6 before joining the body member 1 and the bottom member 2' before reversal. Can be performed by pressing. By this processing, the bottom member 2 ′ before reversal is formed from the planar bottom member blank 32. This step may be performed by directly connecting to the supply portion of the bottom member blank 32 of the bottom curl portion (B) of the paper cup molding machine described above, or the bottom member 2 before reversal after molding performed in advance outside the paper cup molding machine. 'Can also be supplied at the supply portion of the bottom member blank 32 of the bottom curl portion (B) of the paper cup molding machine.
[0015]
Next, as shown in FIG. 7, the bottom member 2 ′ before reversing molded in advance from above is fitted into the bottom member 1, and the joining portion 22 of the bottom member 2 ′ before reversing is folded back of the body member 1. The body member 1 and the bottom member 2 ′ before reversing are joined by thermocompression bonding between the portion 13 and the lower end portion of the body portion 11 to produce the microwave oven paper cup A ′ before reversal.
[0016]
Next, as shown in FIG. 8, the microwave oven paper cup A can be manufactured by turning the bottom surface portion 21U ′ that is convex upward to the bottom and turning the bottom surface portion 21U concave to the bottom.
[0017]
Next, the material used for the body member 1 and the bottom member 2 of the microwave oven paper cup A manufactured by the method for manufacturing a microwave oven paper cup of the present invention has paper as a main strength material and has a thermoplastic resin in the innermost layer. It is based on that.
[0018]
As the paper used as the main strength material, it is preferable to use a cup base paper having good suitability for paper cup molding. The basis weight is not particularly limited, but is preferably in the range of 150 to 300 g / m ^{2 in view} of paper cup molding suitability.
[0019]
The thermoplastic resin used in the innermost layer protects the contents, especially the function that does not leak even when liquid substances are added, and the function that enables the body part to be bonded together and the body part and the bottom part to be bonded by heat sealing It is necessary to have. Specific examples include polyethylene, polypropylene, polyester, nylon, ethylene vinyl alcohol, and ethylene-vinyl acetate copolymer. As thickness, the range of 15-60 micrometers is preferable. These thermoplastic resins are formed in the innermost layer by extrusion processing or laminating processing.
[0020]
For example, the specific material composition includes paper layer / polyethylene resin layer, polyethylene resin layer / paper layer / polyethylene resin layer, foamed polyethylene resin layer / paper layer / polyethylene resin layer, paper layer / polypropylene resin layer from the surface side. , Polypropylene resin layer / paper layer / polypropylene resin layer, paper layer / polyester resin layer, polyester resin layer / paper layer / polyester resin layer, paper layer / nylon resin layer, nylon resin layer / paper layer / nylon layer, etc. .
[0021]
In particular, since the material of the bottom member 2 is deformed into an uneven shape, it is easy to deform, and it is necessary to select a configuration in which cracks and pinholes do not occur at the time of deformation, and a configuration having a polyester resin layer and a nylon resin layer is preferable. .
[0022]
The microwave oven paper cup manufactured by the method for manufacturing a microwave oven paper cup of the present invention is effective as a container for instant foods for heating instant noodles, side dishes, or a beverage container for heating coffee, tea, soup, etc. It is.
[0023]
【Example】
Next, the manufacturing method of the microwave oven paper cup of the present invention will be described more specifically with reference to examples.
[0024]
〔Example〕
As the material of the body member 1, a material of a cup base paper 280 g / m ² / low density polyethylene resin is used from the surface, and as the material of the bottom member 2, a material of the cup base paper 255 g / m ² / low density polyethylene resin is 25 μm from the surface. Material used. First, a bottom member blank 32 as shown in FIG. 3 was punched out, and a bottom member 2 ′ before reversal as shown in FIG. 5-a was formed by press working using a mold 200 as shown in FIG. Similarly, the body member blank 31 was punched out, and the body member blank 31 was wound around a mandrel to form the tubular body member 1. Next, in a process as shown in FIG. 4, a pre-reversed bottom member 2 ′ molded in advance from below the body member 1 is fitted, and the joint portion 22 of the pre-reverse bottom member 2 ′ is connected to the folded portion 13 of the body member 1. The body member 1 and the unreversed bottom member 2 'are joined by being sandwiched between the lower end portions of the body portion 11, and the upper end of the body member 1 is curled outward to form a top curl portion 12 to form the electron before reversal. A range paper cup A ′ was prepared. Further, as shown in FIG. 8, a microwave oven paper cup A having a concave bottom surface portion 21U on the lower side is manufactured by reversing the convex bottom surface portion 21U 'that is convex upward.
[0025]
【The invention's effect】
In the method for producing a microwave oven paper cup of the present invention, first, a bottom surface before reversing that is deformed upward is formed, and then the surface is reversed to form a bottom surface that is concave downward. By manufacturing the paper cup, it is possible to easily manufacture a paper cup in which the shape of the bottom surface portion is deformed to be concave downward. Microwave oven paper cups that have a bottom shape deformed downwardly into a concave shape manufactured by such a method are used when the contents such as beverages and instant food are placed in the paper cup and cooked in the microwave oven. This has the effect of not causing the burnt portion to burn.
[Brief description of the drawings]
FIG. 1 is a partially cutaway cross-sectional view showing an embodiment of a microwave oven paper cup manufactured by the method of manufacturing a microwave oven paper cup of the present invention.
FIG. 2 is a cross-sectional view showing a shape of a bottom member of a microwave oven paper cup manufactured by the method of manufacturing a microwave oven paper cup of the present invention.
FIG. 3 is a development view showing a body member blank and a bottom member blank of a microwave oven paper cup manufactured by the method of manufacturing a microwave oven paper cup of the present invention.
FIG. 4 is a diagram showing a process of forming a general paper cup with a paper cup molding machine.
FIG. 5 is a cross-sectional view of a bottom member before reversal and a partial cross-sectional view of a microwave oven paper cup before transformation.
FIG. 6 is a diagram showing a method for producing a bottom member before reversal by the method for producing a microwave oven paper cup of the present invention.
FIG. 7 is a view showing a method for producing a microwave oven paper cup before inversion by the method for producing a microwave oven paper cup of the present invention.
FIG. 8 is a diagram illustrating a method of manufacturing a microwave oven paper cup after reversal from a microwave oven paper cup before reversal by the method of producing a microwave oven paper cup of the present invention.
FIG. 9 is a partially cutaway sectional view showing a conventional paper cup.
[Explanation of symbols]
A Microwave paper cup A 'Microwave paper cup (before inversion)
P Paper cup (conventional)
Z Yarn twisting part 1 Body member 11 Body part 12 Top curl part 13 Folding part 2 Bottom member 2 'Bottom member 21 before inversion Bottom part 21U Bottom part (after inversion deformation)
21U 'bottom surface before reversing 21Ua bottom surface (after reversing deformation)
21Ub wall surface (after reverse deformation)
22 Joint (bottom member)
31 body member blank 32 bottom member blank R curved surface portion X lower end surface (surface formed by the lower end of the body portion of the body member)
x Distance between lower end surface and bottom surface of bottom surface portion d Maximum depth of bottom surface portion after reversal deformation Maximum height of bottom surface portion before reversal 100 Molding machine 101 Hot air 102 Drum 111-127 mold (mandrel)
200 Mold 201 Upper mold 202 Lower mold

Claims (1)

In the process of manufacturing a paper cup using a body member and a bottom member each made of a blank with paper as a main strength material,
It presses the blank of the bottom member, forming a convex inverted front bottom portion upward from the inner surface of the outer peripheral edge portion of the bottom member, and a substantially vertical joint outer circumferential edge to the lower side of the bottom member A reversing bottom member forming process,
To form a body portion blank is wound into a cylindrical shape of the body member, in the step of forming the top curl curled the upper end of the body portion to the outside, the joint of the pre-inversion bottom member tip disposed to face the lower side of the torso portion of the joint portion by scissors write Muitojiri portion in the body portion and the folded portion of the lower end folded inward of the body portion, the A paper cup molding step in which the body member and the bottom member before inversion are joined together to form a paper cup;
Characterized by comprising a bottom member forming step of forming a bottom portion of the U-shaped from the inner surface side deformed into a concave shape to below the outer peripheral edge of said bottom member by inverting the inverted front bottom portion downward Manufacturing method of microwave oven paper cup.

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